With funding from the Fish and Wildlife Compensation Program, Project Watershed is collaborating with Fisheries and Oceans Canada on several projects focused on rebuilding the Puntledge River summer chinook salmon.
It’s a genetically unique population that is considered to be at risk. Two of these projects will address the impact of high water temperatures on adult summer chinook.
Summer-run chinook salmon adults held at DFO’s Puntledge Hatchery during the summer are at risk of dying before they spawn due to high water temperatures. The hatchery’s water supply is obtained from the Puntledge River, which usually exceeds 20C in the summer, and sometimes reaches 24C.
Such warm water induces stress and disease problems in adult salmon, leading to high mortality rates, poorer quality of eggs in the females that do survive, and lower survival rates for offspring.
As a solution to this ongoing problem, the hatchery has initiated a plan to transport all their summer chinook broodstock to other DFO hatcheries that have cooler water supplies.
Over the past decade, a small portion of Puntledge summer chinook adults have been transported to Rosewall Hatchery and held in 8C groundwater-supplied holding tanks where they experience a survival rate above 95 per cent to spawning.
Another cool-water site exists at Big Qualicum Hatchery (Big Q) approximately 50 km south of Courtenay. This hatchery operates on a deep-water gravity-fed water supply from Horne Lake, which provides water temperatures around 15.5C throughout the summer.
With FWCP funds acquired by Project Watershed in 2010, an additional two holding tanks will be installed at Big Q, allowing a larger portion of Puntledge summer chinook returns to be moved there.
Puntledge River temperatures in late June to early July can exceed 18C, a temperature that makes it too stressful and risky to handle and transport fish out of the hatchery.
To take full advantage of the other cool-water holding facilities, a new chilled-water holding tank will be installed at Puntledge River hatchery in 2011. The tank will allow small batches of returning adult summer chinook to be acclimated to cooler temperatures and then transported throughout the migration period.
Increasing the survival of all hatchery broodstock, by holding them in cooler water, will increase overall summer chinook productivity helping to rebuild the population to their historical abundance.
Funding from the Fish and Wildlife Compensation Program (FWCP) has provided $150,162.00 to design a water chiller and provide holding tanks at Big Qualicum Hatchery. FWCP, is a partnership between BC Hydro, the Province of B.C., and Fisheries and Oceans Canada and was established to address the historical effects of hydroelectric development on fish and wildlife.
Project Watershed’s FWCP-funded Puntledge watershed research, restoration, assessment and protection studies are the outcome of suggestions and recommendations from local stewardship organizations such as the Puntledge River Restoration Committee, industry and government.
For further information about Comox Valley Project Watershed Society, and volunteer and membership opportunities, visit www.projectwatershed.ca.
— Project Watershed